cells: extract info about voronoi cells

In tripack: Triangulation of Irregularly Spaced Data

Description

This function returns some info about the cells of a voronoi mosaic, including the coordinates of the vertices and the cell area.

Usage

cells(voronoi.obj)

Arguments

voronoi.obj

object of class voronoi

Details

The function calculates the neighbourhood relations between the underlying triangulation and translates it into the neighbourhood relations between the voronoi cells.

Value

retruns a list of lists, one entry for each voronoi cell which contains

cell	cell index
center	cell 'center'
neighbours	neighbour cell indices
nodes	2 times nnb matrix with vertice coordinates
area	cell area

Note

outer cells have area=NA, currently also nodes=NA which is not really useful – to be done later

Author(s)

A. Gebhardt

See Also

voronoi.mosaic, voronoi.area

Examples

data(tritest)
tritest.vm <- voronoi.mosaic(tritest$x,tritest$y)
tritest.cells <- cells(tritest.vm)
# higlight cell 12:
plot(tritest.vm)
polygon(t(tritest.cells[[12]]$nodes),col="green")
# put cell area into cell center:
text(tritest.cells[[12]]$center[1],
     tritest.cells[[12]]$center[2],
     tritest.cells[[12]]$area)

Example output

tripack documentation built on July 8, 2020, 5:59 p.m.